Does Capote attempt to show the effects that prison life has on any of In Cold Blood's figures? A quote, or even just general explanation would be really helpful.
He does, especially in regards to Perry Smith. In Part IV of the book, Capote discusses at length Smith's desire to sound intelligent to others. When other prisoners threaten Smith's self-image, he talks about them as if they are unintelligent, never realizing how he appears to others. While Smith already possessed this characteristic before he was imprisoned, the confines of prison certainly exacerbate it.
Similarly, Capote describes Smith's hunger strike when he is in prison, seemingly another attempt on Smith's part to establish his identity and sense of control when placed in prison society. Almost every decision Perry Smith makes while awaiting his fate revolves around how others within the prison will view or remember him.